An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An example particle therapy system includes: a particle accelerator to output a beam of charged particles; and a scanning system to scan the beam across at least part of an irradiation target. An example scanning system includes: a scanning magnet to move the beam during scanning; and a control system (i) to control the scanning magnet to produce uninterrupted movement of the beam over at least part of a depth-wise layer of the irradiation target so as to deliver doses of charged particles to the irradiation target; and (ii) to determine, in synchronism with delivery of a dose, information identifying the dose actually delivered at different positions along the depth-wise layer.

A particle beam adjustment device includes: a position monitor that detects a positional deviation of a particle beam transported from a beam transport section; an interlock device to interrupt irradiation of the particle beam when a positional deviation of the particle beam is detected by the position monitor; a pair of screen monitors that measure position and angle of an axis of the particle beam; a correction electromagnet that controls the axis of the particle beam by adjusting a magnetic field on a basis of a signal indicating the particle beam position and angle measured by the screen monitors; and a beam scanning electromagnet that irradiates an irradiation target with the particle beam. One of the screen monitors is installed outside a treatment room, and the other screen monitor and the position monitor are installed inside the treatment room.

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

A particle beam transport apparatus includes a vacuum duct, at least one magnet controller, and a scanning magnet. The vacuum duct is configured such that a particle beam advances through the vacuum duct. The magnet controller is disposed around a bent portion of the vacuum duct and is configured to control an advancing direction or shape of the particle beam. The scanning magnet is disposed on the downstream side of the magnet controller in the advancing direction and is configured to scan the particle beam by deflecting each bunch of the particle beam. The magnet controller includes a deflection magnet configured to deflect the advancing direction of the particle beam along the bent portion and a quadrupole magnet configured to converge the particle beam. The deflection magnet and the quadrupole magnet constitute a combined-function magnet arranged at the same point in the advancing direction.

An accelerator 4 includes a circular vacuum container including circular return yokes 5A, 5B. An injection electrode 18 is disposed closer to an inlet of a beam extraction path 20 in the return yoke 5B than a central axis C of the vacuum container. Magnetic poles 7A to 7F are radially disposed from the injection electrode 18 at the periphery of the injection electrode 18 in the return yoke 5B. Recessions 29A to 29F are disposed alternately with the magnetic poles 7A to 7F in the circumferential direction of the return yoke 5B. In the vacuum container, a concentric trajectory region, in which multiple beam turning trajectories centered around the injection electrode 18 are present, is formed, and an eccentric trajectory region, in which multiple beam turning trajectories eccentric from the injection electrode 18 are present, is formed around the region.

The present disclosure relates to a magnet pole for an isochronous sector-focused cyclotron having hill and valley sectors alternatively distributed around a central axis, Z, each hill sector having an upper surface bounded by four edges: an upper peripheral edge, an upper central edge, a first and a second upper lateral edges, and a peripheral surface extending from the upper peripheral edge to a lower peripheral line. The upper peripheral edge of at least one hill sector may further include a concave portion with respect to the central axis defining a recess extending at least partially over a portion of the peripheral surface of the corresponding hill sector.

The present invention discloses a homologous dual-energy accelerator and a therapy device comprising the homologous accelerator. The homologous dual-energy accelerator comprises an electron emitting device and an accelerating device, wherein the electron emitting device is located at the input end of the accelerating device, and electrons generated by the electron emitting device are emitted from the output end of the accelerating device after being accelerated by the accelerating device; the homologous dual-energy accelerator further comprises at least one separation deflection device which is arranged on the output end side of the accelerating device and used for changing the motion trail of partial electrons among the electrons accelerated by the accelerating device. The homologous dual-energy accelerator has the advantages that the inventor discovers that the speeds and energy of all electrons are not completely same after the electrons are accelerated by the accelerating device; the inventor uses the separation deflection device arranged on the output end side of the accelerating device through the discovery, the motion trail of partial electrons having relatively low energy level among the particles accelerated by the accelerating device is forcibly changed, the electrons having different energy levels in a homologous electron beam are separated, and two energy levels of electron beams are thus obtained, wherein the high-energy electron beam continues an original path and is used for radiotherapy, and the other path of low-energy electron beam is used for tracking lesions and detecting the therapeutic effect.